Custom IOS transition showing white blank screen while dismissing view controller

Question

I am creating Hero animation like IOS app store click on the app to open detail page , I was able to create presentation animation without any issue but when I tried to dismiss the animation it shows a white background screen for some time, I tried all solution which is listed on stack overflow like adding subview only time, changing modalPresentationStyle to .fullscreen but could not get rid of the white background during dismissal Below is my sample code

let today = TodayDetailViewController()
        today.transitioningDelegate = self
        today.modalPresentationStyle = .fullScreen
        guard let cell = collectionView.cellForItem(at: indexPath) else {
            return;
        }
        let cellFrame = collectionView.convert(cell.frame, to: collectionView.superview)
        modelTransition.originFrame = cellFrame;
        present(today, animated: true, completion: nil);

-- Animation Transition Method

func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        let containerView = transitionContext.containerView
        guard let fromView = transitionContext.view(forKey: UITransitionContextViewKey.from) else { return }
        guard let toView = transitionContext.view(forKey: UITransitionContextViewKey.to) else { return }
        let modalView: UIView = presenting ? toView : fromView

        if(!presenting){

            edgeLayoutConstraints?.constants(to: 0)
            let animator = UIViewPropertyAnimator(duration: duration, dampingRatio: 0.8)
            animator.addAnimations {
                self.edgeLayoutConstraints?.match(to: self.originFrame,
                                             container: containerView)
                containerView.layoutIfNeeded()
                modalView.layoutIfNeeded()

            }
            animator.addCompletion { position in
                switch position {
                case .end:

                    transitionContext.completeTransition(true)
                default:
                    transitionContext.completeTransition(true)
                }
            }
            animator.startAnimation()


        }
        else{

            modalView.translatesAutoresizingMaskIntoConstraints = false
            containerView.addSubview(toView)

            edgeLayoutConstraints = NSEdgeLayoutConstraints(view: modalView,
                                                            container: containerView,
                                                            frame: originFrame)
            edgeLayoutConstraints?.toggleConstraints(true)
            containerView.layoutIfNeeded()
            modalView.layoutIfNeeded()
            let animator = UIViewPropertyAnimator(duration: duration, dampingRatio: 0.8)
            animator.addAnimations {
                self.edgeLayoutConstraints?.constants(to: 0)
                containerView.layoutIfNeeded()
                modalView.layoutIfNeeded()

            }
            animator.addCompletion { position in
                switch position {
                case .end:
                    transitionContext.completeTransition(true)
                default:
                    transitionContext.completeTransition(true)
                }
            }
            animator.startAnimation()
        }